This invention is concerned with odor control technology and more particularly with household, institutional and industrial odor control. In accordance with this invention, odors attributed to a wide variety of human, animal and industrial endeavors can be controlled or eliminated. The odor control process of this invention comprises the application of a solution, of the odor control composition of this invention, to the odor containing substrates, and/or to the industrial waste products.
The application of materials and solutions to substrates for purposes of odor control is common and in fact is thousands of years old, in the most common situation solutions or materials with a pleasant odor are applied to a substrates, for example, to furniture or carpets. In the past the most common method of odor control was to apply solutions which are perfumes to the odor containing substrate. These perfumes did not control the odor but only masked the odor. That is in the prior art the odor was not controlled but instead it was only masked. In contrast in accordance with the subject invention the troublesome odors are not just masked but instead they are chemically controlled or eliminated. This end is effected by treating the substrate with a solution which contains Chloramine-T. With this invention it is possible to eliminate odors resulting from a wide range of sources such as smoking, animal and human fluids, mildew, cooking and industrial by products etc. In its broadest terms, this invention relates to the utilization of a particular Chloramine-T solution which reacts with odor producing molecules as may be contained in a substrate or in an industrial waste product.
Odor control has been a problem which man has addressed for thousands of years, scented or perfumed compositions for odor control are well known in the prior art. Regardless of the widespread usage of these compositions, the problem of effective odor control remains a common and troublesome problem. This situation results from the fact that the prior art solutions do not control the odorous materials as may be in the substrate or part of an industrial waste product. In contrast the composition and related process of this invention reacts with the odorous materials as are contained in the substrate or industrial byproduct and thereby eliminate the same.
The subject invention is concerned with a means whereby undesirable odors can be eliminated by use of the active chlorine in Chloramine-T to react with the odorous material on a molecular level.
In the preferred embodiment, the odor controlling solution for use in this invention incorporates Chloramine-T, a wetting agent and a buffering agent. Using the composition and process of this invention odors in the substrate are eliminated because the odor controlling solution wets out the substrate allowing the active chlorine moiety and the moiety backbone to react with the odorous molecules. The odor controlling composition comprises a solution of Chloramine-T which may contain a wetting agent which is compatible with the Chloramine-T. The wetting agent must not degrade the active chlorine in the Chloramine-T. Preferred wetting agents are generally anionic. In other words the wetting agent in the odor control solution does not degrade the active Cl+ moiety or the backbone moiety which is formed when Chloramine-T goes into solution. If the Cl+ moiety is degraded the Chloramine-T is less effective as an odor control agent.
In accordance with the above discussion this invention is concerned with a process for controlling odors in household, institutional and industrial applications. Perfumed odor control compositions have been used for thousands of years however these solutions did not destroy the odorous materials but instead they only mask the odors caused by these materials. In contrast to this masking of the troublesome odorous material in the prior art, the composition and process of this invention reacts with the odorous molecules. In the prior art odor control compositions are perfumes wherein the odors are masked with synthetic or natural essence. In the subject invention, instead of masking the odor with a perfume, the odor causing molecules are degraded by reaction with the Cl+ moeity and with the chemical moeity which remains after the Cl+ moeity is removed from Chloramine-T. The use of Cl+ is common in odor control, the most common Cl+ producing composition is household bleach. The preferred source of a Cl+ moeity for use in accordance with this invention is Chloramine-T.
Chloramine-T is a common trivial name used to describe a variety of compounds which are based on N-Sodium, N-chloro-para-toluenesulfonamide and N-Sodium, N-Chloeo-Para Benzenesulfonamide. The preferred Chloramine-T for use in this invention is a tri hydrated sodium salt having the following formula. 
As is mentioned above bleach has been commonly used as a source of Cl+ cations which are useful as deodorizers. Because of the problems associated with the use of bleach, i.e. the discoloration of the substrate, it is generally not suitable for use as a deodorizer. In addition the Cl+ cation which is produced by bleach is much more ionic when compared to the Cl+ cation produced by Chloramine-T. That is when compared to the Cl+ cation produced by bleach the Cl+ cation produced Chloramine T is much more covalent and less ionic. As a result of this covalence the side effects produced by the Cl+ cation produced by Chloramine-T are not as severe as those produced by bleach. As a result the Cl+ cation produced by Chloramine-T can be used to deodorize as it does not have side effects such as a strong bleach smell, the undesirable bleaching of the odor containing substrate etc. Further Chloramine-T is more stable than bleach and has a higher Cl+ activity than bleach.
When compared to bleach Chloramine-T is a superior deodorizing agent as the chemical moiety, the backbone, remaining after the Cl+ cation is released by Chloramine-T, further reacts with the odor containing molecule thereby permanently removing it as a potential source of odor. In contrast the chemical moiety which remains after the Cl+ cation is removed from bleach has no ability to react with odor causing molecules.
Most odor causing molecules are mercaptans, sulfides or amine based compounds. Chloramine-T is an excellent agent to eliminate odors which are mercaptan, sulfide or amine based as both the Cl+ cation produced by Chloramine-T and the residual chemical moiety remaining after the Cl+ cation is produced, reacts with the odor causing molecule.
In order for Chloramine-T to be effective it must come into contact with the substance which is responsible for the odor. If the substance which is responsible for the odor is in an environment which makes access difficult i.e. pet stains in a carpet, a means must be provided for bringing the Chloramine-T into contact with the odor causing substance. In many instances when aqueous solution is used as the delivering medium the solution tends to bead up on the substrate. Therefore, when the water component of the solution evaporates the substance in solution is deposited only in localized areas. In the case at hand if an aqueous solution of Chloramine-T were applied to a carpet containing pet stains, the solution would bead up on the carpet, such that when the water evaporated the placement of the Chloramine-T on the carpet would be spotty. Due to this poor placement the two reactive components of the Chloramine-T would not be in position to react with all of the odor causing substance on a molecular basis. That is the reaction of the Chloramine-T with the pet stain would be incomplete, and hence the odor control would be incomplete.
While Chloramine-T is the preferred compound for use in accordance with this invention Chloramine-B may also be used, the formula for chloramines-B is as follows; 
The use of wetting agents with various solutions in order to reduce surface tension is common in the prior art. For example wetting agents are commonly added to herbical solutions to allow the herbicide to wet out plant leaves Likewise the use of wetting agents with insecticides is common.
In accordance with one embodiment of this invention a substance is added to the Chloramine-T solution to reduce the surface tension of the solution. As is discussed above Chloramine-T functions in part by the reaction of the Cl+ moiety with the odor causing molecule. In part, this invention is concerned with the fact that many substances which are suitable for reducing the surface tension of the solution adversely affect the formation of the Cl+ moiety, from Chlormaine-T or degrade said Cl+ moiety once it is formed.
Suitable substances which are useful in accordance with one embodiment of this invention for reducing the surface tension of the Chlormaine-T solution, are synthetic and natural wetting agents. Wetting agents are generally classified as cationic, anionic, amphoteric and nonionic. Because there are thousands of natural and synthetic wetting agents it is impossible to make generalizations as to which would be effective in the composition of this invention. With this caveat it can be said that generally the most preferred wetting agents for use in accordance with this embodiment of this invention are anionic wetting agents, with the next preferred class of wetting agent being a nonionic wetting agents. Amphoteric and cationic wetting agents are least preferred for use with the wetting agent embodiment of this invention.
Regardless of the above comments satisfactory wetting agents may be found in any class of wetting agents.
While the applicant is not sure of all ramifications of how different wetting agents degrade the Cl+ moiety it is felt that functional groups such as alkenes, alcohol, ketone, phenols as may be contained on the base wetting agent molecule are particularly harmful to the Cl+ moiety. Further while it is impossible for the applicant to explore all the ramifications thereof, impurities as may be contained in various commercially available wetting agents can play a significant part in the degradation of the Cl+ moiety. Impurities which are known to facilitate the degradation of the Cl+ moiety are aromatic and conjugated phenols.
The concentration of the wetting agent used in accordance with this invention can be from about 0.1 to 5%. A more preferred concentration for the wetting agent is from about 0.5 to about 1.5%. In order to achieve maximum efficiency in the odor control process the surface tension of the solution must be reduced so that Chloramine-T can reach and react with the odor causing molecules.
A factor in choosing the concentration of the wetting agent is the degree to which it foams. If undesirable foaming occurs anti foamers may be added to the solution.
For stability and for optimum performance as an odor killing agent the pH of a solution of Chloramine-T should be between 6-14, with a more preferred pH range being between 8-9.5 with a most preferred range being between 8.5-9.
As is discussed above the pH range for Chloramine-T solutions for use in this invention can be from about 6-14. Below a pH of 6 the Chloramine-T tends to decompose due to the acidic nature of the medium. While the solution of this invention are effective above a pH of 10.0 solutions having a pH of 10.0 can only be used for industrial applications, due to their caustic nature.
Solutions for use in this invention exhibit excellent stability at a pH range of 8-9.5. This stability is important in domestic applications of this invention where long shelf life is very desirable.
A 5% solution of Chloramine-T naturally buffers itself at a range of about 8.5-9.5. In order to maintain the Chloramine T solution in accordance with these pH ranges it is preferred that the Chloramine-T solution be buffered. The buffering of the Chloramine-T solution further compensates for any change in pH that may result from the acidity of the water which is used to make the solution, the conditions of application, the type of substrate, or industrial waste and the nature of the odor causing molecule.
Buffering agents which are suitable for use in accordance with this invention are sodium bicarbonate, potassium bicarbonate, sodium carbonate, potassium carbonate, acetate buffers (such as sodium acetate), phosphate buffers (such as tri and di sodium phosphate and mixtures thereof, pH blended phosphates, sulfate buffers (such as di and tri sodium sulfate and mixtures thereof.
Because of price, ease of use, low toxicty and their effect on the environment, the above listed sodium and potassium bicarbonate are preferred buffering agents for use in this invention. Buffered solutions are advantageous in that the active ingredients of the odor control solution of this invention can be shipped in powdered form and mixed by the consumer with no adverse effects.
The concentration of the buffer can be from 0% up to the limit of solubility. The preferred range for the concentration of the buffering agent is from about 5% to about 200% of the Chloramine-T in solution. A more preferred range is from about 5% to about 50% with a most preferred concentration being 25-50%.
Chloramine-T has a limit of solubility of about 15% at room temperature in water. However, for shipping in North America it is preferred that the concentration be 10% or less in order to prevent the Chloramine-T from coming out of solution during transport.
For the industrial odor control it is preferred that the concentration of Chloramine-T be about 5-10%. For residential consumer use the concentration of Chloramine-T can be from about .0.25 to about 2.0%, with a more preferred range being from about 0.5 to about 1.0% percent, with the most preferred concentration being 0.75%. These lower concentrations keep the bleach like smell to a minimum but still give the desired odor control.
The composition and process of this invention is suitable for use in controlling the odor which is emitted from a wide variety of industrial sludge such as sewerage treatment sludges, paper making sludges, waste from animal grow outs, animal processing and animal habitats etc.
This invention is particularly suited into the treatment of the sludges which is the byproduct of paper making and in particular the Kraft paper making process.
Chloramine-T is the preferred source of the Cl+ moiety for use in odor control in this invention. As is discussed above, another suitable source the Cl+ moiety is Chloramine-B.
Paper mills are notorious for creating foul odors. In particular the Kraft paper making process produces an odor which is often categorized as a rotten egg smell. In the past society was tolerant of these odors as society often took the position that the smell of a paper mill was the smell of money. The odor of a paper mill is primarily based on odorous mercaptans which the human nose can detect at concentrations which approach one part per billion. These paper mill odors can originate from the holding ponds which are used to hold the sludge which is a byproduct of the paper making process, or from the sludge which results from the treatment of the paper mill stack gases or from solid press. Odors originating with paper mills can often be detected by humans at distances which can exceed twenty miles.
While in the past society was tolerant of these odors in recent times society has become much less tolerant. therefore it is important that these odors be eliminated.
The process and composition of this invention is particularly suited to eliminating paper mill odors due to the ability of Chloramine T to react with mercaptans.
In accordance with the broadest aspects of the paper mill sludge segment of this invention paper mill sludge can be treated with solutions of Chloramine T.
The preferred solvent is water, however, other solvents can be used. The solution which are used to treat Kraft paper mill sludge can have a concentration of from about 3 to about 5 percent with a more preferred range being from about 5 to about 12 percent with a most preferred concentration being 8 percent. All concentrations listed in this application are by weight.
For treating paper mill sludge the preferred solution for use in this invention is an aqueous solution of Chloramine T which is buffered to a pH of about 9.
While a wide variety of buffering agents can be used to preferred buffering agent is potassium or sodium biocarbonite.
Further the solution of Chloramine T may incorporate a wetting agent, it is preferred that the solution incorporate a nonionic wetting agent at a concentration of from about 0.1 to about 5 percent. The caveats and qualifications for wetting agents as are discussed above likewise apply for the treatment of paper mill sludges. The preferred wetting agent for use in conjunction with paper mill sludge treating compositions is an anionic wetting agent sold under the trademark Avanel S-74 by the BASF Chemical Co. of Mt. Olive N.J. The applicant believes that Avanel S-74 is Ethoxylated ROH sulfonate., where R is CH3, CH3 CH2 or CH3 CH2 CH2.
The preferred composition for use in treating paper mill sludges is in accordance with Table 1.
In addition to treating paper mill sludge with solutions of Chloramine T in accordance with the above description these sludges can be treated by dusting the same with powdered Chloramine T. One skilled in the art recognizes this dusting must be done in such a manner as to achieve the proper concentration of Chloramine T in the sludge. In the dusting aspect of this invention the Chloramine T goes into solution in the aqueous component of the sludge which is being treated.